Source : Webster's Revised Unabridged Dictionary (1913)

Syncopation \Syn`co*pa"tion\, n.
   1. (Gram.) The act of syncopating; the contraction of a word
      by taking one or more letters or syllables from the
      middle; syncope.

   2. (Mus.) The act of syncopating; a peculiar figure of
      rhythm, or rhythmical alteration, which consists in
      welding into one tone the second half of one beat with the
      first half of the beat which follows.

Source : WordNet®

syncopation
     n 1: (phonology) the loss of sounds in the interior of a word (as
          in `fo'c'sle' for `forecastle') [syn: {syncope}]
     2: a musical rhythm accenting a normally weak beat
     3: music (especially dance music) that has a syncopated rhythm